Such a method is discussed in WO 2015/120939 A1. When a certain internal pressure is desired in a cavity of a micromechanical component or a gas mixture having a certain chemical composition is to be enclosed in the cavity, the internal pressure or the chemical composition is frequently adjusted during capping of the micromechanical component or during the bonding process between a substrate wafer and a cap wafer. During capping, for example, a cap is connected to a substrate, whereby the cap and the substrate together enclose the cavity. By adjusting the atmosphere or the pressure and/or the chemical composition of the gas mixture present in the surroundings during capping, it is thus possible to adjust the particular internal pressure and/or the particular chemical composition in the cavity.
With the aid of the method of WO 2015/120939 A1, an internal pressure may be adjusted in a targeted way in a cavity of a micromechanical component. It is in particular possible with the aid of this method to manufacture a micromechanical component having a first cavity, a first pressure and a first chemical composition being adjustable in the first cavity, which differ from a second pressure and a second chemical composition at the time of capping.
In the method for targeted adjusting of an internal pressure in a cavity of a micromechanical component according to WO 2015/120939 A1, a narrow access channel to the cavity is created in the cap or in the cap wafer, or in the substrate or in the sensor wafer. Subsequently, the cavity is flooded with the desired gas and the desired internal pressure via the access channel. Finally, the area around the access channel is locally heated with the aid of a laser, the substrate material liquefies locally and hermetically seals the access channel during solidification.